Thanks for the report, I'm able to repro it and I've opened an issue for this. This is one of two things:

To do the reformatting we're actually using TypeScript's formatting services, but TypeScript has since shipped TypeScript 1.0 and we aren't up to date. So there could be some issues in the version of TypeScript we include in NTVS.

The issue could also be that we're running in different JavaScript engines, so we might need to move this out-of-proc and run the formatting in Node which should dramatically speed it up. Either way I expect it to be fixed for the next release.